Some People Believe Running an Electric Fan in a Closed Room Can Kill You
By Chad Upton | Editor
In South Korea, it is a commonly held belief that an electric fan can cause death if it is blowing on you overnight in a closed room.
To prevent “fan death”, the Korean government’s Consumer Protection Board urges everyone to leave a door or window open and use the oscillate function or a timer that automatically shuts the fan off. They also list fan death as one of the top five fatal summer accidents.
The exact origin of this phenomenon is not known for sure, although it allegedly emerged in the 1970s. Some people believe the Korean government may have created this ideology in an effort to save energy during the energy crisis. Oh, and fan death is not limited to just fans, it also includes air conditioners.
South Korean media outlets credit fans and air conditioners for deaths too. In fact, between 2003 and 2005, some 20 deaths were reported to Korea’s Consumer Injury Surveillance System.
Many experts in South Korea firmly believe in fan death, including respected doctors and scientists. South Koreans don’t always agree on why fans can cause death but the following theories are often cited.
Hypothermia is a common one. It’s true that if your body temperature drops low enough, you can die. However, experts claim your body temperature needs to drop by about 16°F (10°C) for this to happen. Since fans don’t actually cool the air, it is not plausible that a fan could cause this temperature drop by convection cooling alone. Not to mention, people frequently asleep outside in much cooler temperatures and survive without question.
That leads to the asphyxiation theory — the belief that somehow these fans reduce the available oxygen in the room. There is no scientific proof to suggest this is true. In North America, the believe is almost the opposite since fans are often recommended to help babies sleep (as a source of white noise).
Another theory is that fan deaths are actually suicides, but reported as fan deaths in the media to spare the family from any cultural shame associated with suicide.
A fourth theory is that the fan combined with hot air creates a convection oven like effect, raising a person’s body temperature, causing them to sweat until they are dehydrated. This theory is interesting because it’s kind of the opposite of the first theory and it could theoretically work, but not likely in South Korea. You see, the highest average temperature in South Korea is about 84°F (29°C), which is still well below body temperature and well below the temperature where the body will start to shut down and die (around 107°F / 42°C). The highest officially recorded temperature in South Korea is 104°F (40°C), just slightly above core body temperature.
The same way a fan doesn’t cool air, it also doesn’t heat it, it just speeds up the transfer of heat between the air temperature and your body. That is why you can cook something in a convection oven at a lower temperature — the fan doesn’t make it hotter, it just improves the transfer of heat. In a traditional oven you need to use a higher temperature setting to make up for the fact that still air doesn’t transfer heat nearly as well.
During extremely hot weather, heat can cause fatalities. Because fans can increase the rate at which your body temperature increases, the EPA does caution against using a fan at temperatures above 90°F (32°C). Don’t mistake this as a suggestion that fans can kill you — you are at risk of dying in extreme heat whether you use a fan or not. In terms of Korean fan death, the 90°F warning is still 6° higher than the average high temperature in South Korea.
It is interesting that this theory is so prevalent in just one country. Most people outside of South Korea do not believe in fan death and there does not seem to be any scientific evidence that a fan will kill you while you sleep.
Do you believe it? Let us know in the comments.
Photo: db0yd13 (cc)